The present invention is directed to a material working machine for wire and ribbon material and particularly to an automatic punching and bending machine. The machine includes a workplate on which at least one working unit is mounted so that it can be swung or rotated in the plane of the plate. A tool carrier forms a part of the working unit and can be moved in a rectilinear manner into the path of the material being worked. The material to be worked is transported along a path forming a work area across the surface of at least one workplate.
Automatic punching and bending machines are known in which the working area, that is a bending station, is located in the center of a workplate and the workplate has receiving bores arranged in a circle about the center of the workplate for the selected insertion of material working or bending units. Each of the material working units includes a tool carrier movable in a rectilinear manner so that it can be moved in and out and the carrier mounts a bending or punching tool oriented toward the center of the workplate. Since the material working units can be swung or rotated about the axis of the receiving bores, its tool carriers can, within certain limits, be adjusted tangentially relative to the center of the workplate. Each material working unit has a control shaft for driving its tool carrier and the shaft extends through the receiving bore to the opposite surface of the workplate. At its end opposite the tool carrier, the control shaft supports a pinion. The pinion meshes with a central gear supported on the workplate and driven by the machine drive. In this particular automatic machine, the working of the material guided in the working area can only take place within the plane of the workplate or in a plane parallel to it, since the central gear prevents access to the working area from the rear surface of the workplate. To solve this problem, it has been suggested to replace the central gear with a chain drive so that the working area is accessible from the rear of the workplate. In such an arrangement, however, a chain wheel must be provided for each receiving bore so that a common chain is wound in a meandering manner around all of the chain wheels and also around a drive gear and this drive arrangement is necessary whether or not the material working units are inserted into each receiving bore. It is also possible and has been proposed to arrange a large flange with an opening at the above-mentioned central gear in the center of the machine, that is, at the support of the central gear, so that additional working operations can be carried out from the rear surface of the workplate through the opening in the flange. By enlarging the opening or passage in the flange, and by using appropriate control members more than one working operation can be carried out in the center or the operations can be staggered laterally. There are limits, however, to the extent to which the opening through the flange can be enlarged and in an extreme case the central gear would become a central toothed wheel. The limitation on size of the opening results from the fact that the support of such a toothed wheel would be very expensive. Further, material working units positioned on the rear surface are relatively heavy and the drive for such units is cumbersome, since it would have to be provided from the outer diameter of the toothed wheel.
In another known automatic bending machine, a subtantially rectangular work plate is provided with an elongated working area located in the center of the plate. Material working units can be positioned on the workplate on both sides of the working area in the plane of the workplate and such units can be oriented in the plane of the workplate in any angular position relative to the working area. Moreover, additional working units can be located in a direction extending perpendicularly to the plane of the plate. The tool carriers for the working unit are operated hydraulically, accordingly, each working unit is connected to the drive through two hydraulic control lines. Due to its elongated working area, this automatic bending machine is better suited for working on elongated wire or ribbon materials than is the first machine mentioned above. This second machine is disadvantageous, however, because the many positions of the material working units in the plane of the workplate is effected by a hydraulic drive which in many instances is undesirable, and, further, the material working units located outside the plane of the workplate can be utilized only in a direction of action perpendicular to the workplate.